44 research outputs found

    Refractive Index of Humid Air in the Infrared: Model Fits

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    The theory of summation of electromagnetic line transitions is used to tabulate the Taylor expansion of the refractive index of humid air over the basic independent parameters (temperature, pressure, humidity, wavelength) in five separate infrared regions from the H to the Q band at a fixed percentage of Carbon Dioxide. These are least-squares fits to raw, highly resolved spectra for a set of temperatures from 10 to 25 C, a set of pressures from 500 to 1023 hPa, and a set of relative humidities from 5 to 60%. These choices reflect the prospective application to characterize ambient air at mountain altitudes of astronomical telescopes.Comment: Corrected exponents of c0ref, c1ref and c1p in Table

    Entwicklung schneller Berechnungsverfahren der Zustandseigenschaften fuer Wasser zur Anwendung bei der Auslegung und Optimierung von energieumwandelnden Anlagen

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    SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

    Industrial benefits of applying HNF in monopropellant satellite propulsion

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    The benefits of advanced HNF monopropellants are discussed. The areas of consideration comprise the operational and performance aspects, the general handling, the benign less-toxic characteristics and the envisaged reduction of manufacturing, test and operational costs. The recently proposed developments and applications of advanced monopropellants for satellite propulsion are reviewed. Besides HNF monopropellants, others will be considered like Ammonium Dinitramide (ADN) and Hydroxyl Ammonium Nitrate (HAN). The evaluation of the parameter matrix justifies the selection of HNF as promising alternative as a less-toxic monopropellant for satellite propulsion. The selection of HNF is mainly based on the fact that HNF offers a higher potential performance growth than other monopropellants. The specific propulsion issues with the application of HNF are presented on both component and system level. The thruster has to cope, among other aspects, with catalyst compatibility and long-term stability. The system components like the feed lines, tanks and others need verification. The GSE however might be simplified significantly. In summary the application of HNF offers a high potential of operational advantages and will justify the required efforts for the introduction and the development of HNF in satellite propulsion

    Optical Methods: An Overview

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    The global water resources and use model WaterGAP v2.2e: description and evaluation of modifications and new features

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    Water – Global Assessment and Prognosis (WaterGAP) is a modeling approach for quantifying water resources and water use for all land areas of the Earth that has served science and society since 1996. In this paper, the refinements, new algorithms, and new data of the most recent model version v2.2e are described, together with a thorough evaluation of the simulated water use, streamflow, and terrestrial water storage anomaly against observation data. WaterGAP v2.2e improves the handling of inland sinks and now excludes not only large but also small human-made reservoirs when simulating naturalized conditions. The reservoir and non-irrigation water use data were updated. In addition, the model was calibrated against an updated and extended data set of streamflow observations at 1509 gauging stations. The modifications resulted in a small decrease in the estimated global renewable water resources. The model can now be started using prescribed water storages and other conditions, facilitating data assimilation and near-real-time monitoring and forecast simulations. For specific applications, the model can consider the output of a glacier model, approximate the effect of rising CO2 concentrations on evapotranspiration, or calculate the water temperature in rivers. In the paper, the publicly available standard model output is described, and caveats of the model version are provided alongside the description of the model setup in the ISIMIP3 framework.</p
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